Rowland Unified Police Chief Don Fernald warned the students to stay away from the crime scene. The body had already been taken away, but white tape marked the outline of the victim killed in the classroom at Shelyn Elementary School.

Welcome to CSI: Rowland Heights, where GATE students are handling the investigation in a murder mystery that will teach them real life science skills. The gifted students meet every Wednesday after school to hone their sleuth skills.

"Once you've stepped into a crime scene, you've changed it forever," Fernald warned the young detectives. "Fortunately, now we have lots of advantages like DNA tests that I didn't have when I started out as a military policeman. Back then, we did everything by hand because we didn't have computers."

Still, the district's police chief said there is no substitute for good detective work.

"Many people have never given a DNA sample, while others never had their fingerprints taken. So you can't count on computers to solve a crime," Fernald said.

So the students have to learn proper crime scene techniques, then pursue the resulting clues.

GATE teacher Pam Hessom said she got the idea from a

teacher's guide developed by the Lawrence Hall of Science at UC Berkeley for grades two to six. Students begin with a teacher-created crime scene.

The scene created by Hessom included footprints, soda cans, sunglasses, jewelry and a hair comb. A trail of fake blood led toward the back door of the classroom.

"Don't grab the pull tab of the soda can, it might have a piece of skin with DNA evidence on it," Chief Fernald advised the students. "You have to be very careful with the evidence or your case could be thrown out of court."

Hessom divided her students into eight investigative teams of four detectives each. Each team gathered around its own section of the crime scene.

Then they began to methodically collect the evidence that they hoped would lead to the murderer. Along the way, the fourth, fifth and sixth graders would learn forensic science, math and chromatography - the use of lab techniques to separate mixtures.

They will use chemistry to make fingerprints stand out, figure out how to isolate a powder trapped in an ice tray and determine what the powder is and learn how to differentiate between animal and human hair, among other things.

"You'll be working with hands-on science and learning real world skills. I was a science major in college, so I'm glad you will be learning chemistry, physics and biology as you use the scientific method in your investigation," said Principal Sarah Opatkiewicz.

"Don't jump to conclusions, you don't want to accuse an innocent person," she added.

Every clue unearthed could be vital in the murder investigation.

Still, the amateur sleuths expressed their concerns to the police chief.

"How do you know if someone is lying," asked one student.

Fernald said some telltales could include body language, shifty eyes, nervous behavior.

"If they talk too much or too fast that can be a sign they are lying," he said. "If it just doesn't look right or it just doesn't feel right, then you know something is wrong."

The Shelyn sleuths have six weeks to solve the mystery.

"My uncle is a real detective, so I can always ask him for some help," suggested 11-year-old Timothy Harlow.